Manufacturing process



Fell 19, 1952 c. J. |NxwE|| ER ET AL 2,586,673

MANUFACTURING PROCESS Filed June 3, 1946 'INVENTOR 5 'fi/M y ATTORNEY Patented Feb. 19, 1952 ofI Ohio Application June s, 1946, serial No. 674,014

3 Claims.

This invention relates to' the'-inanufacturef' of cooperating'matched members vfor'corriplementary @former shape.

"-One olo'j ect of Efthe 'fiinyention vresides-*in'- the lmethod of making a' grinding' wheel'ha'vingla'peripheral grinding" lsurface which is complemenf'tary'vtof the"` form" of another-"grinding"wheel' and d'in Which-llthe form variations, however' small, "of one of "the wheels# are A'accurately reproduced onthe thergrindng v`wheel.

vllnotl'ier object resides fin the method 'of 'inak- -plementary formi-in' Which'onegrinding' wheel is s'urej contact "with fthe' second grinding wheel so l`thatthe*foiirrgivenftd the surface ofthe sec- -ond;grinding-fwheefis exactly complementary to "the form on the" first*grindingwheel` I :Another object resides inthe method oirn'aking a pair of cooperating'intertting 'mer'nbers. in which the membersare' ground fromvv grinding "wheelsof' exactly complementary shape; 'one of "the"Y grinding" Wheels heingj formed by a crusher roll whichfis'fcut or turned by' a'fformcttingftcol Ymade bythe other grinding wheel. l I

Another object -resid'es inthe vmethod I0f mak- "ing'fa'p'air ofmatched grinding'ayvheels bfi 'corn- -`plementary *form* inv which a Crusher Yis used Tto for'nrone'of the grinding vwheelswhich 'can reproduce one orm'ore additional Crushers orff'o'rm Mfto'ols of the-saine form-as the first Crusher. One "of these ferm# tools f is iisedfto" produce a"`c1"usher of the' samef form as thegrindingwheeInien- ""tioned and this'crush'er'is then-used tofornithe *Second grindingwheel cfa; form complementary to ther'st grinding wheel.

O'ther objects andadv'antagesofthe invention `v will bef apparent 'from their ioll'owing?v description, the appendedi claims and fthe 'accompanying "drawing,v in which,

Fig; lis" a frontele'vation ofacrusherfroll'that maybe" employed in accordancewithi theipresent invention to form vthe Fsurface'vfvfthe'- grinding "wheel shown inFig. 2;

(Fig. 2 is a" side elevation showing how'fthe formed grinding "Wheelfis employed" to 'grind a Vform to'ol;

Fig. 3- showsvthe rst crusherfroll after it vhas .Y been -Jtrued toits originalfshape Avfollowing a yperiod lfFig. rsssnows V.the formrtoorcutingfrarsecond crusher roll;

(c1. .5r- 2am Eig." 6 shows?the' "fsecoifid"l orusherrollvandfits @fuseiriniformingzasecondzgrindingffwheel; Fig`.= 'Tishows how;:thesecent1"grindingiwhecl@is "i usedto' grix-idfone""orA afpairfof interttingf mem.- berSJ L Figs? Sifshows 'how thef-rstigr-indingfwheeltis used in'grinding'l'theother interflttingmember;

i Fig;l 9 :shows :af portionfbf aflaniinatiomdieconstructed of f members produced -lbyne' ofthe 10i-r grinding-Wheels and-'fadaptedfor'i exact fintertl ting relationship with the other memberormemfbers' ground -Vin accordance: withfthe'fpresent invehtion; and g Fig. 10 iS-a side v"Wishdwngithrgiii@punch. `The drawinggfin which lthe sameiparts have been designated Y bythe'- same' refernceltters or numerals,` shows the varousl steps p'referred'A in carrying'out the'presentinvention, in Eth-inan- `ufacture "of a pair Jof `'natchedgrinding wheels of exactlyf complementary"peripheralshape; As herein shown anddesc'r'ibed; the' grinding wheels 'are'. used inthe. InaIIIIaKEiDIre" of`cperatingfintelfttigf parts Such aS"-'pn1ch 'lld""' is,` (2'1"v the lile, althugnit willbe' byiusthtassociated "interna-,ing members ct-hr-thn'-sinp1ypunches and dies 'canh-e" made. ""For.e5 a `mp1e, the'method may be used in grindingbrachesor laps 'and l the part that fits in--thebroachedy or lapped' pas- V sage. The method of l this. invention is'particularly adaptedfor use'v in the Aconstruct-.ionfof-'irregularly shaped cooperating meinbers'haying a 1 precise nt with one another vandjwhere fs-mall differences invthe-shapeof the intertting mem- :bersmay be of importance. In'themanufacture of punches r andi' dies, 'for'- example, the 4punch shape should conform exactlyfwith thelshapef'of fferlyinternt-wth? 1the fr'st- '.hasfvbeenidifcultfand hasrequired: `pair'istaking effort-I' andraV gradual shaping process fso that one* member :brought *fluit-by bit Jinto;general conformitywth the other. IThislfgradalhaping proessffespeciallyiiin its lnalfstagesfis usually-done ljy-*lappingfwhicl'r's 1quite-slowfand'te'dious: ,F-'In the 'case offdies'iffor `punching IthiniL stock e is r-r'reces'saryf-ftoiliave a ifveryff'clo'se clearance 4luetiveen'f" hernia-1 ndffefmalelmember offthefdie' set o' e larnce 'eis too largentfany'particula .portiom rpbrtiens, there will be a burrY on the-fstarr'xpingf"-'atVj these ffporticns. Anlextreme@cloetSfofte-requlred,

also, in applying ground parts in broached passages.

Fig. 1 of the drawing shows a rotatable hard abrasion-resistant crusher roll a adapted to be mounted for rotation about its own axis in pressure engagement with a grinding wheel, the grinding wheel or the crusher roll being driven comparatively slowly and the two members operating at the same peripheral speed While the grinding wheel is mounted in the grinding machine in which it is used. Thus the surface of the grinding wheel, which has abrasive grains embedded in a crushable bond, is crushed or formed to have a shape which is exactly complementary to the peripheral sectional shape of the crusher roll. The Crusher roll a, kwhich is preferably made of steel, may be accurately ground by a rapidly rotating grinding wheel operating against the slowly rotating crusher roll, the grinding edge of the griding wheel employed for thispurposefbeing controlledin a precise lmanner by `a precisionA machine-of -a suitable character. The `crusher roll a may beground to precisely the desired shape or form in a ma- 1 chine, for example,v of the general character disclosed in Wolfarth Patent No. 2,248,446. The peripheral sectional shape of the crusher roll a is so made as to conform precisely to a side cf the member to be made in accordance with the process.

The crusher roll a, crushes the grinding Wheel b to shape its peripheral surface exactly complementary to the form given to the Crusher roll a. In some but not necessarily all cases it may be advisable, in order tovcorrect any wear that mayv have taken place on the Crusher roll when it forms or crushes the grinding Wheel b, to retouch or retrue the Crusher roll a in the precisiongrinding machine in which it Was origiv nally formed, to provide the retouched Crusher roll ashcwnV in Fig. 3. This retouched or trued Crusher roll is again operated in peripheral surface pressure contact with the grinding wheel b .to true the grinding wheel so that the grinding wheel vwill have a form exactly complementary to the retrued and perfectly shaped crusher roll a.

, yThe perfectlytshaped grinding Wheel b is then operated in the grinding machine at comparatively high speed to grind a form cutting tool of steel or the like. This form cutting tcol may be a iiat bar, or it may be a circularly formed `tool as illustrated.A In 'this operation, the steel "roll c is slowly rotated and is given a shape corresponding to the shape of the Crusher roll a. If,'in the grinding of the roll c, there has been 'some-slight unevenness or wear in the grinding wheel b, the latter may be trued again by the `retrued crusher roll` a', and the retrued grindl vingwheel b used-in' a finishing grinding operation .to'perfect the surface of the roll c.

Having completed the grinding of roll c, the latter` is cut or notched as indicated at I to pro- "videa circular form tool as shown in Fig. 4 and this form tool is then used in a turning opera- .tion,.in a lathe or mill for example, to cut or shave a Crusher roll d of a material that can be cut by the tool but which is hard and abrasion-resistant. The Crusher roll d may be made oiffa fine-grained'heat-treated cast iron such as Meehan'ite metal. The surface of the Crusher roll d is thus given a form exactly complementary lto Vthe shape of the crusher roll a' or the original'crusher used. The .Crusher roll d is then operated in pressure engagement with another grinding wheel, and at the same peripheral speed by positively driving one of the two members at a comparatively slow speed of operation in the grinding machine in which the parts are later ground. This forms a' grinding wheel c having a shapey which is complementary to the shape of the grinding wheel b. After crushing grinding wheel e to the approximate shape desired, if any wear by abrasion on the crusher roll d has slightly altered the form of that crusher roll, the crusher roll d can be retrued by rotating it in engagement with the stationary form tool c, and the retrued crusher roll d again operated in peripheral surface engagement with the grinding Wheel c to true the latter to precisely the desired shape, and precisely complementary to the shape of the grindling wheel b.

In this way two matched grinding wheels are provided, having formed sur-faces that are complementary in shape to oneanother.

The grinding wheel e is then driven rapidly and performs a grinding operation in a suitable grinding machine, for example in a surface grinder, on a bar of steel or other stock, with the bar or the grinding wheel reciprocating in the direction of the bar axis, thus forming one side of the punch y. The bar is then inverted and the other side of the punch ground by the grinding wheel e. Having completed the punch, or if desired before making the punch, the grinding wheel b is driven at comparatively high speed in a surface grinder or the like to grind one or mo-re depressions in a die member or Vin a row Y of die members or plates h. The die plates h may then be inverted and depressions ground on their opposite sides in the case of a lamination die or the like, and a series of these plates h may then be assembled on a common holding plate, providing a series of die openings j which are of precisely the same form but complementary to the punch g. Any smalldeviations in formation of the surface of the punch are also present in the die opening, since the two are formed by grinding wheels of exactly complementary form, and the punch .and die will therefore intert precisely, without requiring laborious and painstaking lapping or perfecting to obtain the nicety of fit required. It will be understood that in grinding the lamination die plate h, the depth of grind may be controlled precisely so that the width of the die opening formed when a series of different die plates are assembled will have the exact relationship desired with respect to the width of thepunch. Thus, if two or three tenthousandths oi an inch clearance is desired between the punch and die at each side of the die, the depth of grind given by the grinding wheel b may be made that much in excess of one-half the thickness of the punch g.

In the construction of a lamination die or `a number of such dies, a large number of individual die plates and a large number of punches may be made by the grinding operations as previously described, and the punches then assembled on a common mounting plate in their Aproper relationship with respect to the numerous openings in the lamination die assembled `from the plates. If in grinding a large number of these interfitting members some wear takes place in the grinding wheels e and' bythe grinding wheels may again be retrued by operating them slowly in peripheral pressure contact and at the same peripheral speed with the crusher rolls from which they were formed.

it will thus be apparent that interttng or mating parts having exactly complementary shapes may be manufactured in accordance with the present invention Without requiring the laborious lapping and finishing heretofore required in matching such parts together to obtain a precision fit and thin stampings produced will not have the burrs or rough edges caused by excessive clearance between the die parts at some portion or other.

While the method herein described constitutes the preferred manner of carrying out the present invention, it is to be understood that the invention is not limited to the precise steps of the method as herein set forth, and that changes may be made therein Without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

1. The method of making a grinding wheel having an effective peripheral surface exactly complementary in shape to the effective peripheral surface of a first grinding wheel, comprising grinding a cutting tool with the entire effective surface of said rst grinding Wheel to produce on the cutting tool a complement of the entire effective surface of the grinding Wheel, then in a turning operation cutting a rotatable crusher roll with said cutting tool tov provide on said rotatable crusher roll a peripheral surface which is the same in form as the effective surface of the first. grinding wheel, and running said crusher roll in'. peripheral pressure contact with and at'substantially the same peripheral speed asa second grinding wheel to impress the form of the crusher roll into the peripheral surface of the second grinding wheel and thus form that surface exactly complementary to the shape of the effective peripheral surface of the rst grinding wheel.

2. The method of making a pair of matched grinding wheels having formed peripheral surfaces complementary in shape to one another and the grinding wheels having abrasive grains embedded in a crushable bond, comprising making a crusher roll having an effective peripheral contour of the desired form, running a grinding Wheel and said crusher roll in peripheral pressure contact at substantially the same peripheral speed to impress the effective contour of the crusher roll 'into the periphery ofthe grinding wheel and thus produce on their-grinding wheel periphery throughout its widththe complement of the effective contour of the crusher roll, grinding a cutting tool with theientire effective surface of said grinding Wheel to reproduce on the cutting tool the entire effective contour of the crusher roll, and then in a turning operation cutting a second rotatable crusher roll by said cutting tool to produce on the second rotatable crusher roll an exact duplicate of the effective peripheral surface of said grinding wheel, and running the second crusher roll and a second grinding Wheel in peripheral pressure contact at substantially the same peripheral speed to impress the form of the second crusher roll into the periphery of the second grinding wheel and thus form the periphery of the second grinding Wheel throughout its width into a shape that is exactly complementary to the effective peripheral surface of the rst grinding Wheel.

3. The method of making a pair of matched intertting members having complementary surfaces, comprising making a crusher roll having an effective peripheral contour of the :desired form, running a grinding wheel and said crusher roll in peripheral pressure contact at substantially the same peripheral speed to impress the effective contour of the crusher roll into the periphery of the grinding Wheel and thus produce on the grinding wheel periphery throughout its Width the complement of the effective contour of the crusher roll, grinding a cutting tool with the entire effective surface of said grinding wheel to reproduce on the cutting tool the entire effective contour of the crusher roll, and then in a turning operation cutting a second rotatable crusher roll by said cutting tool to produce on the second rotatable crusher roll an exact duplicate of the effective peripheral surface of said grinding Wheel, and running the second crusher roll and a second grinding Wheel in peripheral pressure contact at substantially the same peripheral speed to impress the form of the second crusher roll into the periphery of the second grinding wheel and thus form the periphery of the second grinding Wheel throughout its Width into a shape that is exactly complementary to the effective peripheral surface of the rst grinding Wheel, then grinding one of the members by one of the grinding wheels, grinding the other member by the vother grinding Wheel and intertting the complementary surfaces of the members ground by the grinding wheels.

CARL J. LINXWEILER.

RICHARD Y. MOSS.

JACOB T. WELCH.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,513,758 Hanson Nov. 4, 1924 2,436,527 Polk Feb. 24, 1948 2,456,762 Wilson Dec. 21, 1948 FOREIGN PATENTS Number Country Date 492,591 Great Britain Sept. 22, 1938 

